title: Effects of neuropeptides on feeding initiation in larvae of the silkworm, Bombyx mori.
abstract: In insects, especially phytophagous insects, feeding behavior occurs at a regular frequency. Although a number of physiological studies have revealed various causal factors leading to feeding behavior in insects, little has been demonstrated regarding the regulatory mechanisms underlying insect feeding behavior. To confirm the presence of an endocrinological regulatory mechanism in feeding behavior, we tested the effects of several biologically active peptides on silkworm, Bombyx mori larvae feeding behaviors. To evaluate the effects of the biologically active peptides, we measured the period of latency to the first bite following sample injection into starved Bombyx larvae. Of the chemically synthesized peptides tested, myosuppressin exhibited a prolonged latency, indicating that myosuppressin is a possible inhibitory peptide in Bombyx larvae. In contrast, injections of tachykinin and short neuropeptide F, which are members of the structurally related RF-amide peptide family, had a shorter latency period, indicating that these two peptides are possible stimulatory peptides. In addition, the present study suggests that this bioassay will be advantageous for screening for peptides that regulate insect feeding behavior.
authors.affiliation: Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan. anagashi@mail.ecc.u-tokyo.ac.jp
authors.forename: Shinji
authors.initials: S
authors.lastname: Nagata
authors.forename: Nobukatsu
authors.initials: N
authors.lastname: Morooka
authors.forename: Sumihiro
authors.initials: S
authors.lastname: Matsumoto
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kawai
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Nagasawa
mesh_terms: D000818:Animals; D012831:Bombyx / Q000254:growth & development / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D005247:Feeding Behavior / Q000187:drug effects* / Q000502:physiology; D007814:Larva / Q000187:drug effects* / Q000502:physiology; D008954:Models, Biological; D009479:Neuropeptides / Q000494:pharmacology*; D011930:Reaction Time / Q000187:drug effects; D015320:Tachykinins / Q000494:pharmacology; D014867:Water / Q000494:pharmacology
chemical_list: D009479:Neuropeptides; D015320:Tachykinins; D014867:Water; C076101:neuropeptide F